lockdep: update lockdep_recursion on graph_lock

With the introduction of ftrace, it is possible to recurse into
the lockdep functions via the mcount call. To prevent possible
lockups, updating the lockdep_recursion counter on grabbing the internal
lockdep_lock should prevent deadlocks.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Steven Rostedt 2008-05-12 21:21:00 +02:00 committed by Thomas Gleixner
parent a98a3c3fde
commit bb065afb8e

View File

@ -82,6 +82,8 @@ static int graph_lock(void)
__raw_spin_unlock(&lockdep_lock);
return 0;
}
/* prevent any recursions within lockdep from causing deadlocks */
current->lockdep_recursion++;
return 1;
}
@ -90,6 +92,7 @@ static inline int graph_unlock(void)
if (debug_locks && !__raw_spin_is_locked(&lockdep_lock))
return DEBUG_LOCKS_WARN_ON(1);
current->lockdep_recursion--;
__raw_spin_unlock(&lockdep_lock);
return 0;
}